Fluidic logic system for causing selective flow of a first or second fluid through a common element

ABSTRACT

Fluid flow control arrangements, particularly for a heat exchanger or a reactor in which first and second fluids are directed alternately to a common element such as a heat exchange surface, by means of flow control devices of the fluid logic type thereby avoiding use of mechanical valves and facilitating operation at high temperatures. Preferably two common elements with the associated flow control devices are provided and operated in opposed phase relationship to one another.

United States Patent I 1 1 3,631,873

[72] Inventors Joshua Swithenbank; [56] ReferencesCited David Shaw Taylor, both of Sheffield, UNITED STATES PATENTS England 3,198,431 8/1965 Gesell 137/81.5X p 830,647 3,348,562 10/1967 Ogren l37/8l.5 FM June 5,1969 3,468,330 9/1969 Moore etal. l37/81.5 1 Patented Jan-4,1972 3,478,960 11/1969 Taylor l37/8l.5X 1 8 Na'iml Resemh 3,334,640 8/1967 Phillips 137/815 3,404,542 10/1968 Fineblum 62/324 Primary Examiner-William R. Cline [54] FLUIDIC LOGIC SYSTEM FOR CAUSING Attorney-Cushman, Darby & Cushman SELECTIVE FLOW OF A FIRST OR SECOND FLUID THROUGH A COMMON ELEMENT 8 Claims, 2 Drawing Figs. ABSTRACT: Fluid flow control arrangements, particularly for a heat exchanger or a reactor in which first and second fluids [52] U.S.Cl are directed alternately to a common element Such as a heat 5] I t Cl F15 U12 exchange surface, by means of flow control devices of the n luse: 1H6, fluid logic type thereby avoiding use ofmechanical valves and facilitating operation at high temperatures. Preferably two [50] held of Search 137/815 common elements with the associated flow control devices are provided and operated in opposed phase relationship to one another.

I5 12 23 14 24 I I l 80 31 f F 40 6 33 J '40 n 42 20 I 42 i I 1 I6 32 I 8 l FLUIDIC LOGIC SYSTEM FOR CAUSING SELECTIVE FLOW OF A FIRST OR SECOND FLUID THROUGH A COMMON ELEMENT This invention relates to fluid flow control arrangements and is more particularly concerned with arrangements by which an element, such as a heat exchanger surface or a reactor, may be subjected alternately to fluid flow from different sources.

A particular application of the invention is to heat exchangers for effecting transfer of thermal energy from one fluid medium to another.

Among the objects of the invention is the provision of an improved form of construction capable of operating at very high temperatures and without any mechanical control valves in the fluid flow paths. In the particular case of heat exchangers, further objects include the provision of a high ration of rate of heat transfer to overall volume or mass and within which the setting up of large thermal gradients in the material of the exchanger is avoided.

In accordance with the broadest aspect of this invention a first fluid and a second fluid are directed alternately to a common element, such as a heat exchange surface, by means of flow switching or control devices of the fluid logic type.

In a preferred form of the invention such common element comprises a region lying between first and second fluid flow ports and the flow directions of the first and second fluid flow phases are mutually opposed so that the direction of flow of the first fluid through said region is from the first flow port to the second port whereas the direction of flow of the second fluid through said region is from the second port to the first port. In order to yield a substantially continuous output, at least two separate elements, such as heat exchange surfaces, may be provided and arranged for operation in opposed phase relationship to one another so that the first fluid is flowing in one while the second fluid is flowing in the other and vice ver- The nature of the invention will be more readily understood from the following description of one particular embodiment of the invention, as applied to a heat exchanger, and given by way of illustrative example only with reference to the accompanying drawing wherein:

FIG. 1 is a block schematic diagram of one heat exchanger arrangement in accordance with the invention.

FIG. 2 is a perspective view of one form of flow direction sensitive module suitable for use in an arrangement as shown in FIG. 1.

Referring first to FIG. 1 which illustrated diagrammatically one form of heat exchanger constructed in accordance with the invention, a first fluid input in the form of a high-temperature fluid flow such as a heated gas stream, is directed by a two-directional flow switching device 11 either to follow route a or to follow route b. Route 0 is by way of a first flow direction sensitive module 12 to first fluid flow port 30 of a first heat exchange surface 13 from a second fluid flow port 31 of which the cooled exhaust fluid passes by way of a second flow direction sensitive module 14 to a first exhaust manifold 15. Route b is by way of a third flow direction sensitive module 16 fluid flow port 32 of a second heat exchange surface 17 from a second fluid flow port 33 of which cooled exhaust fluid passes through a fourth flow direction sensitive module 18 to the same exhaust manifold 15.

A second fluid input 19 in the form of a lower temperature or cold fluid flow is similarly directed, in a mutually opposite sense, by means of a second two-directional switching device 20 either to follow route 0 or to follow route d. Route 0 is by way of the direction sensitive module 14 to the second flow port 31 of the heat exchange surface 13 from which surface the heated exhaust fluid passes by way of the first flow port 30 and direction sensitive module 12 to a heated fluid exhaust manifold 21. Route d is by way of the direction sensitive module 18 to the second flow port 33 of the heat exchange surface 17 from which surface the heated exhaust fluid passes by way of the first flow port 32 and the direction sensitive module 16 to the same heated fluid exhaust manifold 21.

The two-directional flow switching devices 11, 20 are controlled to operated in unison but in opposite sense, that is to say, when the device 11 is operative to direct the high-temperature first fluid over route a to heat the exchanger surface 13 and then be exhausted to the manifold 15, the device 20 simultaneously directs the second cold fluid over route d to extract heat from the exchanger surface 17 before being exhausted to the manifold 21. In the opposite operating phase, the device 11 directs the first high-temperature fluid over route b to heat the exchanger surface 17 while the device 20 directs the second cold fluid over route 0 to the other heat exchanger 13.

The two fluid flow switching devices 11 and 20 which each have a common inlet port 40 and alternative output ports 41, 42 may be of any suitable one of the number of already wellknown forms currently employed in fluid logic systems and which utilize the so-called wall attachment" phenomena. Such devices may be arranged for operation by fluid pulses or by continuous small volume directing flows of fluid over the respective control channels as indicated at 28 and 29.

The flow direction sensitive modules 12, 14, l6, 18, each operate to prevent the input fluid supplied thereto for direction to the associated flow port of a heat exchanger from flowing directly to the exhaust manifold for the other fluid and to prevent the exhaust of such other fluid from such flow port of the heat exchanger from flowing towards the input of the first fluid. Thus, referring particularly to module 12 of FIG. 1, this is operative to allow fluid flow from its exclusive inlet port 26 through and out of its common inlet/outlet port 23 while preventing flow of the same fluid directly to the exclusive outlet port 24 or, in the opposite sense or phase, to allow fluid flow entering the common inlet/outlet port 23 to flow to the exclusive outlet port 24 while preventing flow of such fluid towards the exclusive inlet port 26.

Such flow direction sensitive modules 12, l4, l6, 18 may take the form shown in FIG. 2. Such illustrated form comprises a vortex chamber 22 wherein the flow characteristics of gas flowing through the device are profoundly different for the respective forward and reverse directions. Thus, referring to FIG. 2, gas passing inwardly through the common inlet/outlet port 23 will, upon reaching the center of the vortex, have a high angular velocity such as will cause the gas to leave the vortex center through the annular exclusive outlet orifice 24 in directions such as indicated at 25 rather than through the central exclusive inlet nozzle 26. Conversely, gas entering such exclusive central inlet nozzle 26 in the direction as indicated at 27 will, by virtue of its linear momentum, show no tendency to emerge through the exclusive outlet orifice 24 but will, instead, pass into the chamber 22 and emerge by the common inlet/output port 23.

The various fluid chambers associated with the fluid flow control components of elements 11, 20, modules 12, 14, 16, 18 and the heat exchange surfaces 13, 17 are preferably all arranged within a single unitary member or block to provide a compact construction of minimum mass and particularly suitable for mobile use.

While the invention has been described more particularly in connection with its application to heat exchangers, it will be apparent that the invention is also suitable for use in the performance of batch type chemical and other processes. For example, the illustrated common elements in the form of heat exchangers may each be replaced by a reactor or other process unit and the opposite phase of operation used, for example, to regenerate a reactant.

We claim:

1. A fluid flow control arrangement comprising:

a common element having first and second fluid flow ports and means defining a fluid flow path through said element and connected to both said first and second ports to permit flow of a fluid from either of said ports to the other;

a first pure fluid flow switching device having an output port operatively connected to said first fluid flow port to selectively supply thereto fluid from a first source;

a second pure fluid flow switching device having an output port operatively connected to said second fluid flow port to selectively supply thereto fluid from a second source a second common element having first and second fluid flow ports and means defining a fluid flow path through said second common element and connected to both said first and second ports to permit flow of a fluid from either of said ports to the other, wherein said first and second pure fluid flow switching devices are two-direction flow switching devices each having two output ports and wherein the second output ports of the first and second flow switching devices are operatively connected to the first and second fluid flow ports, respectively, of the second common element, both said pure fluid flow switching devices being of the type in which only one output port can be energized at any one time.

2. A fluid flow arrangement according to claim 1, in which said first and second pure fluid flow switching devices each have a common inlet port, said arrangement also comprising first, second, third, and fourth flow direction sensitive modules each having a common inlet/outlet port communicating with an exclusive outlet port and an exclusive inlet port, the common inlet/outlet ports of said first and second modules being coupled respectively to the first and second fluid flow ports of said first common element and the common inlet/outlet ports of said third and fourth modules being coupled respectively to the first and second fluid flow ports of said second common element, said first switching device having first and second outlet ports coupled respectively to the exclusive inlet ports of said first and third modules, said second switching device having first and second outlet pons coupled respectively to the exclusive inlet ports of said second and fourth modules, a first fluid input coupled to the common inlet port of said first switching device, a second fluid input coupled to the common inlet port of said second switching device, a first fluid exhaust manifold coupled to each of the exclusive outlets of said second and fourth modules and a second fluid exhaust manifold coupled to each of the exclusive outlets of said first and third modules.

3. A fluid flow control arrangement according to claim 2 in which said flow direction sensitive modules each comprise a vortex chamber.

4. A fluid flow control arrangement according to claim 3 in which said vortex chamber has a tangentially disposed common inlet/outlet port, a central axially directed exclusive inlet port and an annular exclusive outlet port surrounding said exclusive inlet port.

5. A fluid flow control arrangement according to claim 2 in which said switching devices each consist of a device utilizing the wall attachment phenomena.

6. A fluid flow control arrangement according to claim 2, in which each of said common elements is a heat exchanger.

7. A fluid flow control arrangement according to claim 2, in which each of said common elements is a reactor.

8. A fluid flow control arrangement according to claim 2, wherein said common elements, said flow direction sensitive modules and said switching devices are arranged as a single unitary member. 

1. A fluid flow control arrangement comprising: a common element having first and second fluid flow ports and means defining a fluid flow path through said element and connected to both said first and second ports to permit flow of a fluid from either of said ports to the other; a first pure fluid flow switching device having an output port operatively connected to said first fluid flow port to selectively supply thereto fluid from a first source; a second pure fluid flow switching device having an output port operatively connected to said second fluid flow port to selectively supply thereto fluid from a second source a second common element having first and second fluid flow ports and means defining a fluid flow path through said second common element and connected to both said first and second ports to permit flow of a fluid from either of said ports to the other, wherein said first and second pure fluid flow switching devices are two-direction flow switching devices each having two output ports and wherein the second output ports of the first and second flow switching devices are operatively connected to the first and second fluid flow ports, respectively, of the second common element, both said pure fluid flow switching devices being of the type in which only one output port can be energized at any one time.
 2. A fluid flow arrangement according to claim 1, in which said first and second pure fluid flow switching devices each have a common inlet port, said arrangement also comprising first, second, third, and fourth flow direction sensitive modules each having a common inlet/outlet port communicating with an exclusive outlet port and an exclusive inlet port, the common inlet/outlet ports of said first and second modules being coupled respectively to the first and second fluid flow ports of said first common element and the common inlet/outlet ports of said third and fourth modules being coupled respectively to the first and second fluid flow ports of said second common element, said first switching device having first and second outlet ports coupled respectively to the exclusive inlet ports of said first and third modules, said second switching device having first and second outlet ports coupled respectively to the exclusive inlet ports of said second and fourth modules, a first fluid input coupled to the common inlet port of said first switching device, a second fluid input coupled to the common inlet port of said second switching device, a first fluid exhaust manifold coupled to each of the exclusive outlets of said second and fourth modules and a second fluid exhaust manifold coupled to each of the exclusive outlets of said first and third modules.
 3. A fluid flow control arrangement according to claim 2 in which said flow direction sensitive modules each comprise a vortex chamber.
 4. A fluid flow control arrangement according to claim 3 in which said vortex chamber has a tangentially disposed common inlet/outlet port, a central axially directed exclusive inlet port and an annular exclusive outlet port surrounding said exclusive inlet port.
 5. A fluid flow control arrangement according to claim 2 in which said switching devices each consist of a device utilizing the ''''wall attachment'''' phenomena.
 6. A fluid flow control arrangement according to claim 2, in which each of said common elements is a heat exchanger.
 7. A fluid flow control arrangement according to claim 2, in which each of said common elements is a reactor.
 8. A fluid flow control arrangement according to claim 2, wherein said common elements, said flow direction sensitive modules and said switching devices are arranged as a single unitary member. 